Photographic processing apparatus

ABSTRACT

Processing apparatus for the rapid processing of film, which comprises a tank, an open-ended processing chamber which is composed of two symmetrical sections, which defines a substantially horizontal path for the material to be processed and which is located above the level of the liquid in the tank, an transport roller pair at the entry and at the outlet opening of said chamber, and means for directing streams of processing liquid towards the plane of said path in the processing chamber. The exposing of the liquid to which emerges from the inlet and outlet opening of the chamber is reduced by receiving said liquid in narrow vertical channels which dip in the body of liquid in the processing tank.

United States Patent Aelterrnan et al. 1 Feb. 15, 197 2 [54]PHOTOGRAPHIC PROCESSING 3,192,846 7/1965 Wright ..95/89 X APPARATUS3,372,630 3/1968 Schmidt ..95/94 [72] Inventors: Mnreel 'FramAelterrnan, Mortsel; Emile Primary Emminer-lohn Hora" M su m, H n, f g.Assistant Examiner-Alan Mathews um Attomey--William J. Daniel [73]Assignee: Gevaert-Agta N.v., MOIISCI, Belgium 57 ABSTRACT [22] Filed: M1969 Processing apparatus for the rapid processing of film, whichcomprises a tank, an open-ended processing chamber which is [21] AppI'882,68 composed of two symmetrical sections, which defines asubstantially horizontal path for the material to be processed and [30]Foreign Application Priority Data which is located above the level ofthe liquid in the tank, an transport roller pair at the entry and at theoutlet opening of Dec. 6, 1968 Great Bntarn ..58,l5l/68 said chamber andmeans for directing streams of processing A liquid towards the plane ofsaid path in the processing [52] U.S.CL ..9 5/94 R, 95/89 R h b Thexposing of the liquid to which emerges from [51] lnt.Cl. G03d 5/04 theinlet and outlet opening of the chamber is reduced by [581 FieldofSearch..95/89, 94, 96; 118/419, 429 receiving said liquid in narrow verticalchannels which dip in v the body of liquid in the processing tank.

[56] References Cited UNITED TATES PATENTS v 6 Claims, 4 Drawing Figures3,027,82l I 4/1962 Wright .95/ 89 i w a, 1

I l I 35 It! I\ a 43 4 7 I a 5 7 5s 56 r 62 63 f ,-19

6, I .58 I 7 5? ii 52 GO 5 30- IF ll 5 r I'll-ll PHOTOGRAPHIC PROCESSINGAPPARATUS The present invention relates to a photographic processingapparatus for the fluid treatment of Strip or sheet material, and moreparticularly to an apparatus for rapidly processing image-wise exposedphotographic film, wherein layers of agitated processing liquid contactthe film surfaces to process Processing apparatus for the rapidprocessing of film are known which comprise a tank, an open-endedprocessing chamber which'is composed of two symmetrical sections whichdefines a substantially horizontal path for the material to be processedand which is located above the.level of the liquid in the tank, atransport roller pair at the entry and at the outlet opening of saidchamber, and means for directing streams of processing liquid towardsthe plane of said path in the processing chamber. I In the mentionedapparatus only a minor part of the processing liquid which is fed to theprocessing chamber is carried along by the film as it passes to the nextprocessing station whereas the main part of the liquid emerges from theinlet and/or the outlet opening of the processing chamber in the form ofa curtainto the lower located body of liquid in the processing tank. I

As a consequence of the surface area of the liquid curtain, theprocessing liquid becomes intensively exposed to the atmospheric oxygen,whereby an increased exhaustion of the processing liquid results.Moreover, owing to the strong evaporation of the fixing compositionsulphur dioxide is introduced into the air, so that a corrosiveatmosphere is produced in the apparatus.

The present invention aims at providing an improved processing apparatusof the kind described, wherein the processing liquid is but littleexposed to the air as it flows from the processing chamber to the liquidbath in the tank.

According to the present invention, improved processing apparatus forfluid processing of photographic strip or sheet material is providedwherein there is a processing tank, at least one open-ended processingchamber situated in said tank and defining a substantially horizontalpath above the level of the liquid in'the tank for the material to beprocessed, a pair of transport rollers at the entry and the outletopening of said chamber, means arranged within said chamber fordirecting streams of processing liquid towards the plane of said path,and means defining a narrow channel or channels located to receiveliquid which leaves said processing chamber through its entry or outletopening and descends from between said chamber and the adjacent pair oftransport rollers, 'andto conduct such liquid downwardly into the bodyof liquid in the processing tank.

A said channel or channels at the or each side of the processing chamberand extending transversely of the apparatus between the adjacent pair oftransport rollers and the adjacent entry or outlet opening as the casemay be, of the processing chamber, may be defined by wall means and theupper opening of such channel or channels may extend close.

to the gap between the lower roller and the processing chamber whereas,the lower opening(s) of the channel or channels extend below the levelof the liquid contained in said tank.

According to a preferred embodiment of the invention, one longitudinalwall of the or each narrow channel fits to the lower part of theprocessing chamber and the upper end portion of the oppositelongitudinal channel wall diverges from said one wall to provideawidened inlet opening for the channel:

The invention has been particularly developed in connection withtherapid processing of X-ray film coated on both sides, and used formedical purposes. In automatic film processing apparatus for treatingthe mentioned type of film the requirements are critical, since theprocessing must occur rapidly and the development must be very even fordensities up to 2.8, since subtilities of light and shade play animportant part in the interpretation of the radiographs.

It should be understood, however, that the apparatus according totheinvention is not limited to the treatment of photographic material ofthe mentioned type, and thus other materials, such as industrial X-rayfilm, continuous tone film for graphic purposes, color film,photographic film for air photography, for data-storage, and for otherpurposes, may be processed as well in the apparatus according to theinvention.

In the application of the invention each distinct processing compositionmay be applied to the film by one or more processing chambers, but itwill be apparent that the application of one processing liquid, e.g.,the developer, could occur by a processing chamber whereas theperformance of the other wet processing steps could occur in other ways,e.g., by dip or lick-roller application of the liquid.

Finally, the application of the processing liquid in a processingchamber may also occur to one side of the film only, if such treatmentis sufficient for the processing of the material.

The invention will be described hereinafterby way of embodiment withreference to the accompanying drawings wherein:

FIG. 1 is a sectional elevationthrough a processing apparatus accordingto the invention.

FIG. 2 is a sectional elevation of a processing tank.

FIG. 3 is a front view of a processing chamber, and

FIG. 4 is a plan. view of a processing chamber, the upper section ofwhich isremoved.

Referring to FIG. 1, the processing apparatus comprises a developingstation 10, a fixing station 11, a rinsing station 12 and a drier 13which are located in a housing 14. A film to be processed is introducedinto the apparatus over the supporting surface 40 and follows ahorizontal path through the apparatus indicated by the dash and dot line41. The stations comprise the tanks 15, 1 6 and 17, which are removablysupported at each lateral side by an elongate lateral support 18, andwhich contain processing liquid, the level of which is indicated by thedash and dot line l9. The level of the liquid in each tank is controlledby overflow openings 20, 21 and 22 which are connected by suitable pipesto a drain conduct.

Each tank is provided with at least one open-ended processing chamberlocated above the level of the liquid and intended for applyingprocessing liquid to a film passing through the chamber.

The circulation of the processing liquid in a station occurs in a closedcircuit and, as shown in particular for the fixing station 11, occursthrough a pump 23 which draws liquid from the tank through a filter 39and feeds the liquid through a conduct 24 to the inlet connections 25and 26 which are represented diagrammatically. The inlet 25 is connectedwith the upper section of the processing chamber and the inlet 26 withthe lower section thereof.

Regeneration liquid which is stored in containers 27 and 28 may be fedby means, not shown, to the developing and the fixing tank throughopenings 29 and 30. The rinsing station 12 is continuously .suppliedwith tap water through inlet opening 31. Heating means, not shown, whichare thermostatically controlled, are arranged in the circuits of thedifferent processing solutions in order to keep the temperatureconditions to a constant value.

The drier 13 comprises a plurality of blower tubes 32 which are providedwith a longitudinal slot. The tubes are fed at their extremities withair pressurized by a blower 33 and heated by a thermostaticallycontrolled electric heater 34 so that sheets of air are produced whichare directed towards the path of a film as shown by the small arrows.The circulation of the air in the drier 13 occurs mainly in a closedcircuit whereas a minor part of the air is vented and replaced by freshenvironment air.

Further details about appropriate drier devices may be found in US.Pat1. No. 3,435,539 relating to drier for wetprocessed photographicfilm.

The transport of a film through the apparatus occurs by a plurality ofpairs of rollers, such as the pairs 35 and 36 located in the fixingstation 11 which are provided with a resilient 7 3 covering and whichare urged towards each other under a certain amount of spring loading,e.g., by means of an endless coil spring arranged around the bearings ofthe two rollers. All the pairs of rollers are connected to a commondrive means by way of a worm shaft extending the length of the apparatusand engaging worm wheels which are provided at one extremity of theshaft of each upper roller.

The narrow channels .by which the exposure of the processing liquid tothe atmosphere is reduced and which are represented diagrammatically inFIG. 1, will now be described in detail with reference to FIGS. 2 to 4,and in particular for the fixing station 11. I -'lhe processing chamberis composed of an upper section 42 and slower section 43 which formhollow elongate structures running transversally. of the. apparatus andinto which processing liquid may b efed through inlet connections 25 and26. The walls of both sections which face each other have a corrugatedsurface, whilst the lateral end walls of the upper and lower sectionsrespectively project below and above the lowestand highest points oftheir corrugated walls by about 1 mm. When the two sections aresuperimposed to form a processing chamber, the said end walls abut andthus act as stops, and there remains a gap of about 2 mm. at thenarrowest points between the peaks of opposite corrugations. Inaddition, ribs are provided at the innerside of the corrugated walls toreinforce said walls in the longitudinal direction (transversally withrespect to the film path 41) and to ensure a uniform distribution of theliquid fed into the sections before the liquid flows away throughelongate apertures and towards the film path in a direction obliquelyopposite to the direction of film travel. The apertures are determinedby the longitudinal edges of the corrugated walls and by the folded endsof stainless steel strips 46 and 47 which are fitted to the upper andlower sections by screws 48, and are supported by resilient joint strips49.

At the underside of the section 43 there is provided a boxlikestructure, open at the underside, which is formed by vertical walls 52and 53, and lateral walls 54 fitted at both sides to the walls 52 and53. Small bores 55 near the top of wall 52 permit the establishment ofatmospheric pressure within said structure.

The narrow channel under the entry and the outlet opening of theprocessing chamber are formed by plates 56 and 57, the upper parts ofwhich are bent over about 45, and which are fitted in parallel to thewalls 52 and 53 by means of spacers 58 and 59 at the lateral ends and atthe middle, to define a channel with a width ofabout l mm. The tank isfinally provided with floats6l, 62 and 63 which further reduce thesurface of the processing liquid which is in contact with theatmosphere.

The lateral positioning of both sections of the processing chamberoccurs through the engagement of notches 50 and 51 provided in thelateral walls of the sections, with vertical ribs, not shown, providedon the innerside of the walls of the tanks.

The vertical positioning of the processing chamber is realized in thatthe lateral walls 54 rest with the underside on an elongate rim 60 whichis formed by a projection on the innerside of the lateral walls of thetank.

In the operation of the apparatus, fixing solution is continuouslysupplied by pump 23 to the upper and the lower section of the processingchamber of the fixing station. The streams of fluid emerge symmetricallyto the plane of the photographic material from the elongate aperturesand they are opposed to the direction of movement of the photographicmaterial. In the absence of film material in the processing chamber, allof the liquid pumped into the chamber flows away through the inletopening of the processing chamber. When a film sheet or web is movingthrough the chamber, a minor part of the liquid flows away through theoutlet opening of the chamber. To this minor amount of liquid becomesadded the liquid which is squeezed off the film by the pair of outletrollers. The stream or streams of liquid emerging from the processingchamber are subjected to a very intensive contact with air as theyreturn to the liquid bath in the tank 16. The mentioned contact isdirectly proportional to the height over which the liquid must dropbefore reaching the level 19 of the liquid in the tank. The

said height is considerably reduced in the improved arrange la: 1 D 2 2;(s)

wherein h is the rise of the liquid in respect of the liquid level inthe tank 7 g is the gravitational acceleration d is the flow per timeunit sis the cross section of the channel The fonnula 1) is calculatedfrom the known formulas:

v Vfi giving the outstream velocity at the level of the liquid in thetank, and

D=v.S giving the flow per time unit.

Since the parameters g and D, as well as the desired rise h are known,the cross section S of the channel may be calculated from formula l Inthe present example, a rise of about 25 mm. was obtained 'for a channelwith a cross section of 1.5X340 mm. and a flow rate of 400 ccs./sec.,whereby the height over which the emerging liquid was subjected to aircontact was reduced by half.

This numerical example counts for the channel located at the entryopening of the processing chamber. At the outlet opening the rise of theliquid was less on account of the smaller volume of liquid flowing atthis place.

An increased rise of the liquid at the outlet channel may be obtained byusing a channel with reduced cross section in respect of the channel atthe entry opening of the processing chamber but, as said alreadyhereinbefore, on account of changing conditions during the operation ofthe apparatus according to the presence or absence of a film in theprocessing chamber, an optimum rise of the processing liquid in thechannels will not be obtained.

In the operation of the apparatus, it has been noticed that thearrangement according to the invention reduced the oxidation of theprocessing liquid, and in particular the oxidation of the developer by afactor 4 at a temperature of 40 C., so that the oxidation of thedeveloper amounts only to about 0.8 times that of conventionalprocessing apparatus with dip tanks.

From the diagrammatic representation of the apparatus in FIG. 1 it canbe seen that the processing chamber of the rinsing station is alsoprovided with narrow channels. Although the channels at this place donot serve the purpose of reducing the oxidation, they considerablyreduce the evaporation of the rinsing water which is supplied at arelatively great flow rate, so that the moistening of the atmosphere ismaintained at an acceptable degree.

The same processing chamber arrangements are used in the developingstation but it can be seen there that two such chambers are provided inorder to obtain the necessary developing time. The deflected ends of theopposite walls of the two adjacent narrow channels loosely support afolded cross over strip 65 consisting of a piece of stainless steel.

The narrow channels which have been described hereinbefore have auniform cross section. It will be apparent that a rise of the liquidlevel may also be obtained by channels or channellike structures whichslightly converge from the inlet opening towards the lower outletopening, or which have a uniform wider cross section over the fullheight which is only tapered near the outlet. It isevident that for suchembodiments, the smallest value of the cross section of the channel mustbe considered for formula (1). It should be noted, however, that theincreased surface area of the liquid in each channel may give rise to aless good reduction of the oxidation effects.

The width, or occasionally the narrowest section-of the channels may beadjustable. The adjustment may occur by displacement of one wall inrespect of the other. Such displacement may be done by -a parallel orangular displacement of one longitudinal wall of the channel in respectof the other, but it may also be done by deformation of one wall inrespect of the other, e.g., by pinching together the longitudinal wallends defining the outlet opening. The adjustment may also occur by theintroduction of space filling members such as small rods, plates, etc.,in the channel, or by partially closing the outlet opening. 1

The walls defining the channel may be provided with ribs or the like toreduce frictional contact with the floats.

Finally, the opposite walls of the channels, e.g., the walls 56 and 57of the channels in the fixing station, may form part of,

or be constituted by other members. For instance, the walls 56 and 57may form part of the longitudinal walls of the tank which are so formedthat they run closely parallel with the walls 52 and 53, or the walls 56and 57 may be formed by the side walls of vertically extending floats.

In the embodiment shown, the upper end portions of the opposite channelwalls 56 and 57 were deflected over about 45 to bring the upper edge ofeach wall next to the vertical plane passing through the axes of theadjacent pair of rollers. The upper portion of one or each wall may bedeflected over other angles, and may occasionally have a flexibleextremity acting as a scraper on the appertaining roller, so as toadditionally remove liquid from the roller periphery. The widened inletopening of the vertical channels may be closed at the lateral endsthereof and the wall means forming such lateral closing may extendupwardly to lie flush with part of the ends of the rollers extendingbetween the shafts of the rollers and the processing chamber.

In the described apparatus, the direction of the streams of processingliquid was opposite to the travel of the film sheets through theapparatus. It should be understood that the present invention is notlimited to a processing chamber wherein the processing liquid is appliedin the described way, and thus the invention includes also apparatuswherein the layers or streams of processing liquid flow onto the filmpath in the same direction as the film sheets. Furthermore, said streamsof processing liquid may be produced by several narrow openings arrangedat each side of the film path, rather than by one opening as shown inthe Figures and said narrow opening may also be in the form of aplurality of adjacent circular or elongate small openings and referencemay be taken to various patents and other publications in this field forfurther details.

We claim:

1. A processing apparatus for fluid processing of moving photographicstrip or sheet material comprising a tank for processing liquidincluding at least one processing chamber disposed above the liquidlevel in said tank and defining a generally horizontal path for thepassage therethrough of said material, a pair of transport rollers ateach of the inlet and outlet openings of said chamber, means in saidchamber for projecting streams of processing liquid toward said path,and collecting means for said liquid comprising a downwardly directednarrow channel provided at at least one of the openings of said chamber,and defined by a pair of spaced apart longitudinal walls, the wallnearer said chamber terminating at said opening and the other walldiverging from said nearer wall adjacent its upper end to form anenlarged mouth for said channel and terminating in close proximity tothe periphery of said lower roller, said channel emptying into saidtank.

2. Processing apparatus according to claim 1 including one of saidnarrow channels at each of the entry and outlet openings of theprocessing chamber, and wherein the two nearer longitudinal walls areconnected by vertical sidewalls which extend to the bottom of theprocessing chamber to constitute with said nearer walls a boxlikestructure which is open at the underside and extends at its lower endinto the processing liquid in the tank,

3. Processing apparatus according to claim 2, wherein an opening isprovided in said boxlike structure at a point above the level of theliquid in the tank to expose the interior of said structure toatmospheric pressure.

4. Processing apparatus according to claim 1, wherein at least twoprocessing chambers are arranged in said tank, each adjacent pair ofsuch chambers being separated from each other by a pair of transportrollers.

5. Processing apparatus according to claim 1 wherein each such channelextends substantially the full width of said chamber.

6. Processing apparatus according to claim 1 wherein said processingchamber comprises a passageway defined by two spaced apart sinuouslycurved walls, the peaks and valleys, respectively, of said curved wallsbeing in registration along said processing path.

1. A processing apparatus for fluid processing of moving photographicstrip or sheet material comprising a tank for processing liquidincluding at least one processing chamber disposed above the liquidlevel in said tank and defining a generally horizontal path for thepassage therethrough of said material, a pair of transport rollers ateach of the inlet and outlet openings of said chamber, means in saidchamber for projecting streams of processing liquid toward said path,and collecting means for said liquid comprising a downwardly directednarrow channel provided at at least one of the openings of said chamber,and defined by a pair of spaced apart longitudinal walls, the wallnearer said chamber terminating at said opening and the other walldiverging from said nearer wall adjacent its upper end to form anenlarged mouth for said channel and terminating in close proximity tothe periphery of said lower roller, said channel emptying into saidtank.
 2. Processing apparatus according to claim 1 including one of saidnarrow channels at each of the entry and outlet openings of theprocessing chamber, and wherein the two nearer longitudinal walls areconnected by vertical sidewalls which extend to the bottom of theprocessing chamber to constitute with said nearer walls a boxlikestructure which is open at the underside and extends at its lower endinto the processing liquid in the tank.
 3. Processing apparatusaccording to claim 2, wherein an opening is provided in said boxlikestructure at a point above the level of the liquid in the tank to exposethe interior of said structure to atmospheric pressure.
 4. Processingapparatus according to claim 1, wherein at least two processing chambersare arranged in said tank, each adjacent pair of such chambers beingseparated from each other by a pair of transport rollers.
 5. Processingapparatus according to claim 1 wherein each such channel extendssubstantially the full width of said chamber.
 6. Processing apparatusaccording to claim 1 wherein said processing chamber comprises apassageway defined by two spaced apart sinuously curved walls, the peaksand valleys, respectively, of said curved walls being in registrationalong said processing path.